weathering

The process by which rock materials are broken down by physical or chemical processes. 

mechanical

weathering

The breakdown of rock into smaller pieces by physical means (ways)

frost action

The alternate freezing and thawing of soil and rock

ice wedging

A type of frost action.    

Water seeps into crack in rocks; when the water freezes it expands and the ice pushes against the sides of the cracks, causing the cracks to widen.  

The cycle repeats over and over, each time the cracks get bigger until finally the rock breaks.

abrasion

The grinding and weathering away of rock surfaces through the mechanical action of other rock or sand particles.

exfoliation

The process by which entire sheets of rock peel away from a large body of rock because pressure is removed.

agents of mechanical weathering

• ice
• water
• wind
• gravity
• plants
• animals

chemical weathering

The process by which rocks break down as a result of chemical reactions

acid precipitation (rain)

Rain, sleet or snow that has a higher concentration of acid than normal

groundwater

Water that flows through rock underground.

oxidation

When oxygen in the air reacts with the iron is rocks